Gas pilot light



Patented Apr. 24, 1934 1,956,268 v GAS PILOT LiGn'r Edward J. Brady, Swarthmore, and Joseph B.

Clafley, Philadelphia, Pa.-, assignors to The,

- United Gas Improvement Company, Philadel phia, Pa-., a corporation of Pennsylvania ApplicationAjpril 24, 1 933, SerialNo. 667,653 3 Claims. (01 158-115) The present invention relates to gas pilot lights. A common method of igniting gas range burners is to provide a centrally located pilot burner con-' tinuously supplied with a small flow of gas, and at the time of turning on the gas to the cooking burner,'supplying the pilot burner with a larger flow of gas to produce a torch flame which. is projected to the cooking burner and ignites the gas issuing from its ports.

Widely used devices for this purpose employ a needle valve orifice for controlling the small pilot flow through a passage which bypasses a valve operated to provide the larger or torch flow.

It has been found that the control of the pilot flow which is in the neighborhood of 0.2 to 0.3 cubic foot per hour by means of a needle valve or other orifice or short passage leads to very considerable trouble due to outage of pilot lights from stoppage of the control orifice or short passage by gum or dust because of "the narrow width required to secure the low rate of flow. For instance, the needle valve orifice of a widely used lighter when adjusted for the above low flow under a gas pressure of 3% inches of water is about .oooza inch.

Such outage of pilot lights is a source of expense to the gas distributing company and is very dangerous in the case of modern appliances in which burners are intermittently turned on by 0 automatic means. I

It has also been found that if the pilot fiow is controlled by passage of the gas through a long capillary groove formed as a spiral in .the surface of a disc pressed tightly against a second surface a compact control unit may be provided which will accurately control the flow to the pilot and will be subject to very greatly decreased danger of stoppage. The principal object of the present invention is to provide an improved torch ignition device in which the needle valvecontrol of the small pilot flow is replaced by control effected by means of passage through a capillary groove like passage 'of sufficient width and depth to greatly diminish the danger of stoppage and of sufficient length to reduce the flow to the pilot to the desired extent.

Ajfurther object of the invention is to provide such an apparatus in which the use of a stufling box for the torch flow control valve is made unnecessary. v

Other objects of the invention will appear from the following description which will be given in connection with the accompanying drawing which forms a part of this specification, and in which-- Figure 1 is a cross sectional view of the torchflow and pilot control of the invention.

Fig. 2 shows the apparatus of Fig. 1 connected to the burner bar and to a pilot burner,

Fig. 3 is a view of a detail. v

Referring t6 Fig. 1, 1 generally indicates the lighter body, provided with the threaded lug 2 adapted to be connected in a tapped hole in a burner bar of a gas range.

The body is provided with the threaded cylindrical recess indicated at 3 and an annular channel'4 arranged at a lower level than the recess.

A cylindrical lug 5 rises above the channel-to the level of the bottom of the recess 3: The lug 5 is faced to provide a flat surface at 6.

7 generally indicates a corrugated disc of spring-material, for instance phosphor-bronze, the corrugations being arranged in a. spiral, and are indicated at 8. a

A threaded flanged cover is arranged to'screw down intothe recess 3 as a gland and tightly hold the flat periphery of the disc 7.' The disc is provided with spring waves indicated at 10 which are so formed that when the cover 9 is screwed in, the disc is held tightly on the surface 6 by their spring action, and a spiral groove like capillary passage is providedextending from the inlet gas passage 11 to the annular channel 4. The annular channel 4 is connected by the outlet passage 12 to the threaded opening. 13, which is. adapted to receive the pipe (not shown in this figure) leading to the pilot burner.

14 is a lever arm swinging on the pin 15 as a fulcrum and extending through a slot 16 in the cover 9. The lever arm is .provided with a yoke at 17 through whichextends the rod 18 which is attached to the center. of the disc '7. The nut 19 threaded on to the end of therod 18 rests on the arms of the lever arm yoke. '20 is a collar on the rod 18. forming a support for the lever arm 14. The lever arm 14 is provided with the button 21. The cover 9 may be provided with a threaded and opening 22 fitted with the threaded plug'23 to facilitate assembly.

Referring to Fig. 2, this figure shows the apparatus of Fig. 1 connected to the burner bar of a gas range and to a pilot burner.

24 generally indicates the apparatus of Fig. 1 connected in a-tapped hole in the burner bar 25. 26 is the, pipe leading to the pilot burner, 27. 28 is a cooking burner supplied with gas from the burner bar through pipe- 29 as controlled by cock no Inthe operation of the apparatus of Figures 1 and 2 gas flows continuously from the burner bar to the ignited pilot. From the burner bar it passes through the inlet passage 11 to the inner endof the spiral passage formed by the corrugations of. the disc 7 and the surface 6. From this spiral passage the gas flows into the annular channel 4 and thence by way of the outlet passage 12' to the opening" 13 and the pipe 26 leading to the pilot burner 27. The travel through the capillary passage controls the flow of the gas and secures the desired low rate of flow to the pilot burnen. The capillary passage is made of sufficiently large width and'depth to avoid danger of stoppage from dust-and gums and sufficiently longto reduce the gas flow to the desired extent.

A capillary groove like passage .035 inch wide and having a cross sectional-area equivalent to that of a circle .035 inch .in diameter and 17 inches-long will be satisfactory for gas pressures of from 3 to 4 inches of water. Such a length of capillary can be readily provided within a circle 1% inches in diameter so that the apparatus may be of small size. t 1 These dimensions are given purely for illustration and we do not wish to be limited to them, as for different conditions of pressure and flow these dimensions should be varied. In general the cross section of the passage should have a high ratio of cross sectional area to periphery.

Whenthe cooking burner is to be ignited gas is supplied to-it through pipe 29 by openingcock 30. At the same time the button 21 is pushed down and the leverarm 14 acting throughwod 18 liftsthe disc 7 off the seat formed by the surface 6. This permits a larger flow of gas to the annular channel 4 and thence through passage 12, opening 13 and pipe 26 to the pilot burner 27, projecting a torch flame to the burner 28 and igniting the gas issuing from the ports.

The button 21 is then released and the spring action of the disc '7 restores it to its seat on the surface 6, the small pilot flow continuing through the capillary passage.

The apparatus of Figures 1 and 2 provides a simple means of igniting gas burners, which may beeconomically manufactured. It may be readily applied to existing appliances to replace igniters with needle valve controlled pilot flow.. It has the advantage of not requiring a stufiing box for the valve controlling the larger torch flow. It may be readily taken apart and cleaned if necesfigure is over times the width of the annular Different pressure and flow conditions may be taken care of by providing discs with various widths and depths of corrugations and length of spiral, to form capillary passages of various cross sectional areas and lengths. We prefer to have the width and depth of the capillary passage at least .02 inch to avoid danger of stoppage. This orifice of widely used needle valve pilot controls.

As an indication of the efficiency of the employment of a long groovelike capillary channel for the control of pilot flow instead of a needle valve from a standpoint of stoppage the following is cited In a prolonged test a pilot controlled by a spiral capillary gropve of the approximate dimensions first above given for illustration for the capillary passages in Fig. 1, was operated burning coal gas inoculated with oxides of nitrogen to form sufficient gum particles to give an accelerated test. Simultaneously and in parallel, drawing gas from the same storage holder, were operated needle valve pilots of a widely used type adjusted for the same low typical range pilot flow under the same gas pressure.

The capillary controlled pilot burned continuously for twenty-five days and was still buming at the end of that period without apparent diminution of flow, while the best needle valve controlled pilot went out through stoppage of the needle valve twenty-three times during the same period. After each stoppage it was cleaned out and reignited. Its stoppage was not always noted immediately, as for instance when it occurred at night, so that the comparison is much more favorable to the groove control than above indicated.

It will be obvious to those skilled in the art to which the invention relates that modifications may be made in details of construction and arrangement and matters of mere form 1C0 without departing from the spirit of the invention which is not limited to such matters, or otherwise than the prior art and the appended claims may require.

We claim:

1. A gas pilot light control comprising, in combination, a chambered fitting for interposi- 1 tion between a burner bar and a pilot, light burner and having a gas way ported to the chamber centrally thereof and another gas way ported to one side of the center, a diaphragm in the form of a spiral corrugation having one end of the grooveof the spiral corrugation in communication with the centrally disposed port and the other end thereof in communication with the other port whereby a spiral passage is normally provided for the passage of gas, and a push button device connected with the diaphragm and adapted to lift the same to provide a torch gas flow. .3

2. A gas pilot light control comprising, in combination, a valve device having a push button, a diaphragm supported at its rim and having a corrugation in the form of a spiral groove, said diaphragm connected with the push button device and serving as the spring thereof, and connections for leading gas normally through the spiral passage provided by the corrugatio'n and adapted to by-pass the spiral passage when the diaphragm is raised by the push button to provide a torch flow.

3. A gas pilot or like burner comprising, in combination, a valve device, operating means for the valve. device, said valve comprising a diaphragm held at its, rim and having a spiral groove, said diaphragm connected with theoperating means, and connections forleading gas normally through the spiral passage provided by the groove and adapted to by-pass the spiral groove when the diaphragm is raised by said operating means to provide a torch -flow.

EDWARD J. BRADY. JOSEPH B. CLAFFEY. 

